CWE-177Variant

Improper Handling of URL Encoding (Hex Encoding)

Draft in the CWE catalog · 15 CVEs mapped

15
CVEs mapped
7.0
Median CVSS
What it is

The product does not properly handle when all or part of an input has been URL encoded.

Recent examples
7.5cvss
CVE-2026-76172

CVE-2026-76172 - HIGH Severity Vulnerability

fast-uri is a URI parser for Node.js. During parsing it runs a legacy decoding pass over the scheme component and never re-escapes the result, and serialization writes the scheme back out verbatim, unlike the host component which is re-escaped. As a result an input whose scheme carries percent-encoded slashes parses as a scheme with no authority, so the parsed host and error are both undefined, yet resolving or normalizing that same input emits a network-path reference whose authority is attacker-chosen and re-parses to that host. An application that allowlists on the parsed host, or treats a reference with no authority as safe to resolve against its base, gets the opposite of what it checked, giving an off-site redirect, server-side request forgery, or address-policy bypass. The legacy decoder also expands non-standard escape forms, widening the issue past upstream filters, and control characters in the scheme can reach the output as raw carriage return and line feed. The affected versions are 2.3.1 up to but not including 2.4.5, 3.0.0 up to but not including 3.1.6, and 4.0.0 up to but not including 4.1.3. The issue is fixed in 2.4.5, 3.1.6, and 4.1.3, which reject a scheme that is not valid after decoding. Users should upgrade to a patched version.

HIGHno explanation yet
0%
epss
6.5cvss
CVE-2026-67448

CVE-2026-67448 - MEDIUM Severity Vulnerability

Mailpit is an email testing tool and API for developers. From 1.29.0 until 1.30.6, Mailpit's server/server.go origin middleware checks the raw RequestURI for the /api/ prefix while Go's ServeMux routes using the percent-decoded URL path, and server/websockets/client.go configures websocket.Upgrader.CheckOrigin to return true. A malicious website can request /%61pi/events, skip corsOriginAccessControl(), reach the /api/events WebSocket handler, and receive live message IDs, Message-Id values, sender and recipient fields, subjects, tags, and body snippets from an unauthenticated default Mailpit instance after the user visits the site. This is a regression of the earlier WebSocket origin protection and does not affect deployments protected by --ui-auth-file. This issue is fixed in version 1.30.6.

MEDIUMno explanation yet
0%
epss
8.1cvss
CVE-2026-15371

CVE-2026-15371 - HIGH Severity Vulnerability

Velociraptor's web GUI allows specifying a custom type for columns in tables. The URL type takes the cell value and forms a URL which can be clicked in the GUI.The code does not limit the schemes allowed in this URL , allowing an attacker to specify a JavaScript scheme exposing the user to XSS.

HIGHno explanation yet
0%
epss
The record
Technical detail
CWE ID
CWE-177
Abstraction
Variant
Structure
Simple
Status
Draft